Rotary toothbrush



April 25, 17933- c. c. v. sMn-H 1,905,656

ROTARY TOOTHBRUSH Filed June 19, 1931 Patented Apr. 25, 1933 UNITED lSTATES PATENT ooFfFlcE CARL C. V. SMITH, F ClOPENEAGEN, DENMARK, ASSIGNOR TO ALFA KLARA SMITH, 0F

COPENHAGEN, DENMARK ROTARY Toormziwsn Application led .Tune 19,

This invention relates to tooth brushes and has particular reference to rotary tooth brushes which are adapted to cleanse the teeth of a user in the proper manner with an up and down stroke.

The general object of the invention 1s to provide a simple device of th1s nature which is simple in construction and, therefore, may be economically manufactured commercially, and which is so constructed that the brush member is readily removable to permit thorough cleansing or sterilizing of the same or to permit the use of different brushes with the same handle and actuating means.

The device of the invention comprises essentially a tubular handle, a brush member having a stem removably carried by the handle, a brush-actuating crank removably attached to the end of the brush stem, and a mouth guard removably carried by the handle. An important feature of the invention is the novel manner in which the various elements are constructed to removably attach the brush-actuating crank to the brush stem and also to removably attach the mouth guard to the handle. Another important feature is the cup-shaped combination cap and stop member carried by the brush stem and which functions to prevent liquids from getting into the handle and also cooperates with the actuating crank to prevent longitudinal movement of the brush stem within the handle.

Other objects and features of the invention will be apparent from the following detailed description. Referencemay be had to the accompanying illustration which discloses several embodiments of the invention. In the drawing:

Fig. l is a perspective view of the preferred embodiment of the device with the parts thereof in assembled relation;

Fig. 2 is a perspective view showing the details of construction of the mouth guard and the manner in which it cooperates with the handle;

Fig. 3 is an enlarged partial section of the device of Fig. l;

Fig. 4 is a partial section of a modified form of the device;

1981. Serial No. 545,698.

Fig. 5 is a partial pers ective view of the brush stem of the modi cation;

Fig. 6 is a partial perspective view of the actuating crank of' the modification; and

Fig. 7 is a partial section ofanother modification of the device.

Referring to Figs. l to 3 of the drawing, the device of the invention comprises essentially a tubular handle 1, a brush member 2 rotatably carried thereby, an actuating crank 3 removably attachable to the end of the brush member, and a mouth guard 4 which is removably att-achable to the handle. As clearly illustrated in Fig. 3, the brush member-comprises a stem 5 having a recess 6 of substantial length at the forward end thereof for the reception of the usual twisted wires 7 of the brush. The wires may be suitablyv fastened within the stem recess in any desired manner. In the present instance, I have shown the usual construction in which brush bristles 8 are held firmly between the twisted wires but it will be obvious that any other form of brush may be utilized. For example, a brush having rubber bristles or the like may be used. It is also to be noted that since the brush member is removable, as will be clearly set forth hereinafter, such member may be constructed to massage the gums of the user. An impor tant feature of the present device is the cap 9 which I have provided at the end of the brush to firmly hold the ends of the twisted wires in place. This cap is so constructed that the wires when firmly wedged therein are prevented from loosening and the bristles are therefore prevented from detaching themselves from the device. This is an important feature since, as will be readily perceived, the normal rotary action of the brush member during operation will have a tendency to unwind or loosen the twisted wires. v

In order to tightly close the forward end of the handle and at the same time prevent longitudinal movement rearwardly of the brush stem therein, I provide a cup-shaped member 10 which serves this dual purpose. As illustrated in Fig. 3, this-member is suitably attached to the brush stem at the forwardlend thereof immediately adjacent the brush. It will be observed that this member is so shaped that it snugly fits over the end of the handle and serves as a cap to completely close or seal the handle and thus prevent fluids or semi-fluids from entering the handle during the use of the device. It will also be obvious that this member acts as a stop to limit the longitudinal movement of the brush stem with respect to the handle.

In further accordance with the invention, the brush-actuating crank 3 of the device is formed at one end to provide a suitable compressible socket or chuck 11 which is adapted to receive the protruding end of the brush stem. As will be clearly understood from the drawing, this socket is provided by cutting longitudinal slits 12 to form resilient lingers 13 which are compressible to grab the end of the brush stem. In order to obtain a firm and positive connection be tween the actuating crank and the brush stem, I provide a slidable ring or collar 14 which when moved forward is adapted to compress the socket 11 and cause fingers 13 to frictionally engage the end of the stem. It will be obvious that while I have disclosed herein a manually operable crank for actuatingthe brush, any suitable actuating means, such as a motor, may be utilized. In any case, the same connection between the actuating means and the brush stem, as is disclosed herein, may beused.

The mouth guard .4 of the device comprises a tubular portion 15 and a guard portion 16 in the form of a kbent plate. |Ihe purpose of this member is, of course, to protect the delicate skin and tissues of the users mouth from contact with the rotating brush which might otherwise cause undesirable irritation and soreness of such skin and tissues. The guard portion may take any shape but it is essential that it conform generally with the shape of the brush. The tubular portion 15 is adapted to fit over and slidably rei ceive the handle of the device for removable attachment thereto. A pair of diametrically opposite slits 17 are cut in the tubular portion for a purpose which will be apparent hereinafter.

lo enable the user of the device to rmly hold the handle against rotation, bearing in mind the fact that the users hands might be moist during operation of the device, I provide a pair of diametrically opposed linger-receiving members 18 on the handle. These members are preferably formed from a't pieces of metal which may be firmly affixed to the handle in any suitable manner. These members are each formed to provide an arcuate finger-receiving portion 19 and an integral narrowed extension 20 (see Fig. 2) The purpose of the narrowed extensions Ais to provlde a locking arrangement to firmly attach the mouth guard to the handle and prevent relative rotary movement therebetween. The extensions are` adapted to reside within the corresponding slits 17 of thc mouth guard when the latter is mounted. upon the handle.

Considering the manner in which the device is assembled and used, it will be apparent that the brush member and mouth guard may be attached to the handle simultaneously. The parts are so dimensioned that the tubular portion 15 of the guard is adapted to fit snugly between the finger-receiving portions 19 and the cup-shaped member 10 on the brush stem (see Fig. 1). In other words, the tubular portion of the guard is firmly held between these two members to prevent longitudinal movement of the guard and to firmly mount it upon the handle. It, therefore, becomes apparent that the guard and brush member must be assembled with the handle at the same time. The actuating crank may now be firmly attached to the end of the brush stem, it being understood that the slidable collar 14 will be at the crank end of the socket during attachment and will be slid toward the brush end of the device to afford the previously mentioned positive connection between the elements. In attaching the crank to the brush stem, it is essential that the end of the socket 11 firmly abut against the adjacent end of the handle. Since the end of the socket acts as a second stop, it will be apparent that the brush stem is firmly held against longitudinal movement in either direction with respect to the handle. In using the device, the handle is, of course, held in the fingers of one hand while the actuating crank is turned with the other. If power operated actuating means is used, one hand only will, of course, be necessary to use the device.

It is important to note that by means of the simple construction just described, the

brush member may be readily removed to cleanse the same. By virtue of the novel construction of the brush member, a smooth stem surface is provided which enables thorough cleaning and sterilizing. The construction also permits the use of different types of brushes with the same device. A brush member having any kind of bristles may be used with the device. While a mouth guard stationarily mounted upon the handle could be used, the novel structure of the present device facilitates removal of the brush member and also enables the use of different guards.

In Figs. 4 to 6, there is disclosed a modified form of the device,.wherein the manner in which the actuating crank is attached to the brush stem diifers in detail from that already described. As is clearly illustrated in Figs. 4 and 6, the actuating crank is formed to provide a different type of compressible socket 21, such socket having the external surface thereof threaded as at 22. In this instance also, the socket is provided with longitudinal slits 23 to provide a pair of resilient fingers 24. These fingers are oppositely disposed and are provided at their .ends with inwardly extending projections 25.

Anotches 26, the fingers will resiliently force their projections 25 into the notches to firm-k ly hold the end of the stern. In order to insure a positive connection between the crank and the stem, I provide an internally threaded collar 30 which is normally carried upon the handle of the device, the end of the handle being preferably flared outward as at 3l to prevent detachment of the collar therefrom. After the crank has been suitably attached to the brush stem in the manner set forth, the collar may be threaded upon the socket 22 to hold the resilient fingers 24 thereof in proper position to keep projections 25 within notches 26. It will be apparent that removal of the actuating crank ma only be effected by forcing the resilient ngers 24 outward after the collar 30 has been moved. This is accomplished by merely turning the brush stem relative to the crank so that the resilient fingers 24 will be forced outward, the projections 25 being moved out of notches 26 and forced apart the width of the stem diameter. The stem may then be readily slid from the socket of the crank.

In Fig. 7, I have shown a somewhat similar modification of the construction in question wherein a different form of socket 32 is provided on the actuating crank, such socket being formed to provide a single resilient arm 33 having a depending projection 34 at its end. The end of the handle is flared as before and carries a slidable sleeve 35. The brush stem is notched at 36 to receive projection 34. The manner of assembly of the parts in this instance is similar to the previously described modification. In this instance, however, the locking sleeve 35 is merely slid back and forth and is not adapted for threaded engagement with the crank socket.

It will be apparent that I have rovided a device which is constructed of a ew simple parts which may be easily and quickly assembled or disassembled. The device is of course capable of many changes and modifications which are deemed to be within the spirit and scope of the invention.

I claim:

1. A tooth-brush comprising an elongated handle member, a guard member having a tubular portion adapted to lit snugly over said handle member, a brush member having a stem extending axially through said handle member, a cup-shaped member carried by said stem adjacent the brush and adapted to snugly fit over an end of said handle member and abut against said tubular portion to hold the same upon said handle member, and means removably attachable to the end of said stem and adapted to abut against the other end of said handle member, whereby said brush member may be firmly attached to said handle.

2. A tooth-brush comprising an elongated handleV member, a pair of fin er-receiving members thereon, a guard mem er having a tubular portion adapted to fit snugly over said handle member and abut against said finger-receiving member, a brush member having a stem extending axially through said handle member, a cup-shaped member carried by said stem adjacent the brush and adapted to snugly fit over an end of said handle member and abut against said tubular portion whereby said guard member is firmly mounted on said handle member, and brush actuating means removably attachable to the end of said stem and adapted to .abut against the other end of said handle member, whereby said brush member may be firmly attached to said handle.

CARL CHR. V. SMITH. 

